How can I make a non-handwriting text appearing like if someone writes it?
This is how I did it (this may not be the best solution).

Bevel factor works with non-cyclic curves. So you need to do this one character at a time. 


Create the text object of the character
convert to curve (alt + c)
uncheck cyclic (U) option in curve object data
Extrude the unconnected node to have a closing edge manually
increase depth to a non-zero value


Now you should be able to control the curve length with bevel factor.